<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    @font-face {
      font-family: "iconfont";
      src: url("./fonts03/iconfont.ttf");
    }

    .iconfont {
      font-family: "iconfont";
      font-style: normal;
      font-size: 100px;
    }

    .icon {
      display: inline-block;
      width: 20px;
      height: 20px;
    }

    .music::before {
      content: "\e664";
    }
  </style>
</head>

<body>
  <!-- 直接通过内容(字符实体) -->
  <i class="iconfont">&#xe654;</i>
  <i class="iconfont">&#xe664;</i>

  <i class="icon"></i>

  <!-- 不使用字符实体的方式展示出来(伪元素) -->
  <i class="iconfont music"></i>
</body>

</html>